The present invention relates to poultry leg/back processing operation apparatus and technique, particularly with respect to improvements therein for accomplishing high-speed automated reduction of eviserated and dressed poultry carcass back-half members, commonly called the "saddle" which is comprised of a poultry back with joined thighs and legs depending therefrom further which may be delivered as such from previously accomplished partial processing operations as taught say by the whole poultry carcass transverse halving-cut method of Schacht shown in FIG. 4 of his U.S. Pat. No. 3,675,272 dated July 11, 1972, by the instant technique and apparatus to yield therefrom three separated pieces being the two joined leg and thigh sections removed from the single back section thereof in such a manner as is herein taught to also respectively remove along with the thigh portions of each joined leg and thigh section piece, substantially absent any bone fragment or chip contamination, those highly desirable fleshy morsels known as "oysters" which are appended the outer end of each thigh and removed therewith from their positions of repose within shallow laterally disposed elongated back section cavities proximity of the thigh ball-and-socket joint vicinity of the back section vertebrae and generally parallel thereto wherein upon consideration of the foregoing as hereinafter more fully detailed, it is to be understood that the term poultry is used in the generic context to mean fowl, including but not necessarily limited to old and young chickens, at least small turkeys, and ducks and guineas.
Traditionally, in the automation of poultry sectioning operations the various machines developed therefor have employed in various embodiments the means of piston-driven reciprocating rotary knives or saws in accomplishing the cutting and dismemberment of one carcass section from another, exemplary of which type machine would be that as taught by Baker in his U.S. Pat. No. 4,019,223 dated Apr. 26, 1977, and closer to point as regards applicant's instant teaching would be the double saw blade cutting station operation shown in FIG. 5 of Schacht cited supra for accomplishing the automated separation of joined drum stick and thigh sections from either side of the rear half or saddle of a poultry carcass. When either rotary saw or knife means are employed for accomplishing automated poultry carcass sectioning operations, however, as a consequence of inherent carcass weight and structural variations which translates to automated process guidance and positioning problems with respect to consistent orientation of sequentially fed carcass members to the cutting blade so as to present a line of cut of tissue only, which frequently results in the cutting or crushing of bones with the production of bone fragment or chip contamination in the processed meat which is objectionable and for which there is presently no known particular means or satisfactory method enabling a facilitated removal of any such bone fragment or chip contamination, the singularly most satisfactory way to eliminate the potential bone fragment or chip contamination problem in processing poultry sections for human consumption is to employ dismemberment apparatus and technique enabling operation in such a manner so as to accomplish automated poultry carcass sectioning without the problems of bone cutting or crushing. A machine developed to accomplish automated whole poultry carcass sectioning into the normally available commercially consumed pieces with an objective of reducing by eliminating the problem and hazard of producing poultry pieces with bone fragment or chip contamination therein was that as set forth in instant applicant's prior co-inventive teaching described in U.S. Pat. No. 4,016,624 to Martin et al. dated Apr. 12, 1977, which incorporates a machine station as illustrated in FIGS. 17 through 21 thereof providing saddle member conveyance and guide means to move the back-half carcass member past pre-positioned stationary knife means and sever the principal tendons which hold the balls of the thigh bones within back section vertebra sockets therefor by which the joined leg and thigh sections are connected to the carcass back section, and thereafter during continued guided conveyance spread the joined leg and thigh sections away from each other with respect to the centrally intermediate connecting carcass back section therebetween and upon a sudden stop of each joined leg and thigh section with respect to the continually moving centrally intermediate back section thereby yank from either lateral side thereof the respective joined leg and thigh sections without the production of bone fragments or chips but with the further object of jerking out along with simultaneous dismemberment of the thighs from the back section removal respectively of the oysters from their back section cavities along therewith.
The instant invention, likewise to accomplish intact leg and thigh with joined oyster removal from poultry carcass saddle members also employs the methodology of pre-positioned severing blades to prevent bone fragment or chip contamination, but further employs differential speed screw conveyor means in combination with a modified back section chain conveyor means in such a way that the oysters rather than being yanked are peeled from their back section cavities by the effects of an increasingly smooth variable speed differential, in which regard certain prior art disclosures do show the use of a screw conveyor means with pre-positioning of fixed blades in poultry processing operations such as taught in U.K. Pat. No. 1,320,958 dated June 20, 1973, to Johnson-Stephens, Ltd., wherein a conical helix conveyor screw provided with various guide rod bars is employed to receive, direct, and advance a suspended plucked chicken carcass to a rotary neck-slitting blade for accomplishing craw removal, and at the other carcass extremity as taught by Harben, Jr., in his U.S. Pat. No. 4,118,829 dated Oct. 10, 1978, the use of a pre-positioned fixed blade in combination with co-operative screw conveyor advancement means to accomplish the opening cut on suspended plucked poultry carcasses for eviseration is taught.
Some of the features of the instant invention have, in some respects, both structural and/or functional similarities to various of those teachings separately set forth in the prior art disclosures heretofore cited and briefly discussed. However, as will hereinafter be pointed out, the instant invention is distinguished from said earlier inventions in one or more ways in that the present invention has utility features and new and useful advantages, applications, and improvements in the art of poultry processing machines and methods not heretofore known.